Description

Filter SuppressWarningsFilter uses annotation @SuppressWarnings to suppress audit events.

Rationale: Same as for SuppressionCommentFilter. In the contrary to it here, comments are not used comments but the builtin syntax of @SuppressWarnings. This can be perceived as a more elegant solution than using comments. Also, this approach maybe supported by various IDE.

Usage: This filter only works in conjunction with a SuppressWarningsHolder, since that check finds the annotations in the Java files and makes them available for the filter. Because of that, a configuration that includes this filter must also include SuppressWarningsHolder as a child module of the TreeWalker. Name of check in annotation is case-insensitive and should be written with any dotted prefix or "Check" suffix removed.

Notes

SuppressWarningsFilter can suppress Checks that have Treewalker or Checker as parent module.

Examples

To configure the check that makes tha annotations available to the filter.

<module name="TreeWalker">
              ...
<module name="SuppressWarningsHolder" />
              ...
</module>
        

To configure filter to suppress audit events for annotations add:

<module name="SuppressWarningsFilter" />
        

Full configuration:

<module name="Checker">
  <module name="TreeWalker">
    <module name="SuppressWarningsHolder" />
  </module>
  <module name="SuppressWarningsFilter" />
</module>
        

Example:

@SuppressWarnings({"memberName"})
private int J; // should NOT fail MemberNameCheck

@SuppressWarnings({"MemberName"})
@SuppressWarnings({"NoWhitespaceAfter"})
private int [] ARRAY; // should NOT fail MemberNameCheck and NoWhitespaceAfterCheck
        

It is possible to specify an ID of checks, so that it can be leveraged by the SuppressWarningsFilter to skip validations. The following examples show how to skip validations near code that has @SuppressWarnings("checkstyle:<ID>") or just @SuppressWarnings("<ID>") annotation, where ID is the ID of checks you want to suppress.

Example of Checkstyle check configuration:

<module name="RegexpSinglelineJava">
  <property name="id" value="systemout"/>
  <property name="format" value="^.*System\.(out|err).*$"/>
  <property name="message"
    value="Don't use System.out/err, use SLF4J instead."/>
</module>
        

To make the annotations available to the filter.

<module name="TreeWalker">
  ...
  <module name="SuppressWarningsHolder" />
  ...
</module>
        

To configure filter to suppress audit events for annotations add:

<module name="SuppressWarningsFilter" />
        

Full configuration:

<module name="Checker">
  <module name="TreeWalker">
    <module name="SuppressWarningsHolder" />
    <module name="RegexpSinglelineJava">
      <property name="id" value="systemout"/>
      <property name="format" value="^.*System\.(out|err).*$"/>
      <property name="message"
        value="Don't use System.out/err, use SLF4J instead."/>
    </module>
  </module>
  <module name="SuppressWarningsFilter" />
</module>
        

Example:

@SuppressWarnings("checkstyle:systemout")
public static void foo() {
  System.out.println("Debug info."); // should NOT fail RegexpSinglelineJava
}
        

Example of Usage

• Checkstyle Style
• Google Style

Package

com.puppycrawl.tools.checkstyle.filters

Parent Module

Checker